Abstract: AIM: To evaluate the effect of cortex fraxini total coumarin on relieving pain in treatment of pa-tients with primary acute gouty arthritis which belongs to the sign of dampness obstructing connecting vessel of TCM. METHODS: Cortex fraxini total coumarin was in-volved in a randomized, double-blind, placebo parallel control, dosage-reaction design and superiority test. The total case number of observed primary acute gouty arthritis with the sign of dampness obstructing connecting vessel was 109, which included 36 cases of low-dosage group, 36 cases of high-dosage group, and 37 cases of control group.RESULTS: After 5 day-treatment of cortex fraxini total coumarin, both the evaluation of patients on the im-provement of joint pain grades and the appraisement of physicians on relieving joint tenderness were superior to those in the placebo group, and they were in a dosage-re-latedmanner.But the disappearance rate of joint pain and joint tenderness had no difference between two groups. CONCLUSION: Cortex fraxini total coumarin has some-what pain relieving effect on acute gouty arthritis.

Key words: cortex fraxini total coumarin, primary a-cute gouty arthritis, sign of dampness obstructing connect-ing vessel, relieve pain, explorative clinical trial